• 한국진공학회지
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• 제18권1호
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• pp.49-53
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• 2009

층간 절연막으로써 연구되고 있는 SiOC 박막의 화학적 변화에 대하여 살펴보았다. SiOC 박막의 형성은 알킬기와 수산기에 의한 극성분자의 조합에 의해 무분극성의 박막을 형성할 수 있고 무분극성에 의한 비정질 구조를 형성함으로써 유전상수의 감소를 유도할수 있다. 박막의 화학적인 특성은 이온의 변화에 의한 결정구조의 변화로 결정할수 있고, 화학적인 변화의 분석은 FTIR에 의한 탄소함량변화로부터 무분극성의 영역을 유추해 내었다. 전기적인 특성은 박막 내에서의 전자의 특성을 알아보는 것으로써 화학적인 특성과 반드시 일치하는 것은 아니다 유량변화에 따른 SiOC 박막의 전기적인 특성을 분석함으로써 화학적 특성의 변화와 어느 정도 상관성이 있는지를 조사하였다. SiOC 박막은 열처리 후 대체로 누설전류가 증가하는 것으로 나타났고 특히 탄소의 함량이 급격히 증가하는 샘플이 존재하였다. 그러나 탄소의 함량이 증가하였으나 누설전류는 상대적으로 작게 나타나는 것으로 보아 화학적인 관점에서 탄소의 증가는 박막의 구조변화에 따른 효과로 직접 전류에 기여하지 않는다고 볼 수 있다.

• Journal of Electrochemical Science and Technology
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• 제9권1호
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• pp.37-43
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• 2018

In order to improve current efficiency and decrease energy consumption in the electrosynthesis of ammonium persulfate, electrolytic properties of four cation exchange membranes, namely, the $JCM-II^{(R)}$ membrane, $Nafion^{(R)}$ 324 membrane CMI-$7000^{(R)}$ membrane and a self-made perfluorosulfonic ion exchange membrane (PGN membrane) were investigated using a sintered platinized titanium anode and a Pb-Sb-Sn alloy cathode in a self-made electrolytic cell. The effect of cell voltage and electrolyte flow rate on the current efficiency and the energy consumption were investigated. The results indicated that the PGN membrane could improve current efficiency to 94.85% and decrease energy consumption to $1119kWh\;t^{-1}$ (energy consumption per ton of the ammonium persulfate generated) under the optimal operating conditions and the highest current efficiency of the $JCM-II^{(R)}$ membrane, $Nafion^{(R)}$ 324 membrane and CMI-$7000^{(R)}$ membrane were 80.73%, 77.76% and 73.22% with their lowest energy consumption of $1323kWh\;t^{-1}$, $1539kWh\;t^{-1}$ and $2256kWh\;t^{-1}$, respectively. The PGN membrane has the advantages of high current efficiency and energy power consumption and has sufficient mechanical strength with the reinforced mesh. Therefore the PGN membrane will has good value in popularization in the industrial electrosynthesis of ammonium persulfate in the future.

• 한국멀티미디어학회논문지
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• 제5권4호
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• pp.393-398
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• 2002

기존의 MPEG-1 오디오 부호화 방식 이 사용하는 비트 할당 알고리듬은 비트 할당이 종료될 때까지 최소의 MNR을 갖는 서브밴드를 탐색하는 과정을 반복적으로 수행한다. 따라서 비트 할당을 수행하는데 필요한 전체 계산량의 상당 부분을 서브밴드 탐색 과정이 차지한다. 본 논문에서는 서브 밴드 탐색을 좀 더 효율적으로 수행 할 수 있는 방안을 제 시 하고, 기존의 방식과 음질과 계산량 측면에서 비교하고자 한다. EBU(Europe Broadcasting Union)가 제공하는 음질 평가용 CD에 수록되어 있는 팝 음악 신호를 사용하여 실험한 결과, 128 kbps의 비트율로 오디오를 압축하는 계층 2 알고리듬 환경에서, 제안한 방식이 필요로 하는 계산량은 ［1］의 방식이 필요로 하는 계산량의 42% 정도이며, MNR로 측정한 두 방식간의 음질 차이는 0.2 ㏈ 정도로 별 차이가 없음을 확인할 수 있었다.

• 사회경제평론
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• 제31권3호
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• pp.239-270
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• 2018

본 연구의 분석결과는 다음과 같다. 첫째, 패널회귀분석을 통해 원 하청기업의 노동소득분배율 결정요인을 추정한 결과, 거래집중도, 외주가공비, 자본집약도, 시장점유율 변수는 유의한 부(-)의 영향을 미치고, 노조조직률과 연구개발비 변수는 정(+)의 영향을 미치는 것으로 추정되었다. 특히, 연구개발비는 투자가 이뤄진 해당연도(t기)에는 노동소득분배율에 유의하지 않거나 부정적인 영향을 미쳤으나, 시간이 흐름(t-1기, t-2기)에 따라 긍정적인 영향을 미쳤다. 둘째, 지난 11년간(2006~2016)의 원 하청기업의 노동소득분배율은 모든 연도에서 하청기업이 더 높았다. 원청기업보다 임금수준이 낮은 하청기업의 노동소득분배율이 더 높다는 것은 하청기업의 지불능력이 개선되지 않고는 원 하청기업 간 임금불평등을 해소할 수 없다는 것을 시사한다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.522-530
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• 2002

We have already known, neural progenitor cells exist not only in the developing brain, but in certain spots in adult CNS in mammals, so it will be of great value to find out some compounds which can interfere these cells proliferation ability. In this research, we observed that ginsenoside $Rg_1$ can not only enhance neural progenitors' proliferation ability in vitro, but increase neurogenesis in adult mouse dentate gyrus in vivo. Firstly, we set up neural progenitor cells' culture system from embryonic rats' hippocampus and prove their feature through immunocytochemistry. Then by using MTT assay, we found that when growing with ginsenoside $Rg_1(0.5\~2.5{\mu}mol/l)$, the progenitor cells' survival rate nearly doubled, furthermore, we proved that this increase was due to the increment of cell proliferation through $^3H-thimidine$ incorporation assay, hence, we drew the first conclusion: ginsenoside Rg1 has the ability to stimulate neural progenitor cells' proliferation in vitro; in order to observe this compound's effect in vivo, we devised the following experiment: after administering ginsenoside Rg1 (5, 10 mg/kg, once a day) intraperitoneally for two weeks, we examine the number of BrdU positive cells in the dentate gyrus of mice, and found that Rg1 could increase the number of proliferation cells significantly in vivo. From these studies, we are quite sure about Rg1's effects on the proliferation ability of neural progenitor cells both in vitro and in vivo, certain targets of the compound and its underlying mechanisms are in progress.

• 디지털융복합연구
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• 제19권12호
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• pp.133-143
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• 2021

차터스쿨을 통한 혁신 사회 지속가능성에도 불구하고, 차터스쿨은 여전히 복잡한 정치 상황 아래에서 성장과 쇠퇴를 반복하고 있다. 2011경에 일어난 차터스쿨의 성장에도 불구하고, 이를 정치적인 관점에서 연구한 연구는 찾아 보기 힘들다. 따라서 정치제도와 정치시장 분석틀을 사용하여, 본 연구는 미국의 주정부 자료를 바탕으로 정치적 제도와 차터스쿨 성장과의 관계를 회귀분석을 활용하여 분석하였다. 그 결과 주지사의 소속정당은 차터스쿨의 수에 영향을 미치고 있었으며, 민영화지지 단체, 주지사의 소속정당과 1인당 소득은 차터스쿨의 집행 점수에 통계적으로 유의미한 관계를 나타냈다. 또한 주정부 내 교원 노동조합의 등록비율, 주지사의 소속정당과 1인당 소득은 차터스쿨의 보장된 재정지원에 영향을 미치는 중요한 요인으로 작용하였다. 결국, 본 연구의 결과를 통해 정치적 제도가 교육에 중요한 요소임을 확인할 수 있었다.

• 대한조선학회논문집
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• 제58권5호
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• pp.303-313
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• 2021

Recently, quality control of the Liquefied Natural Gas Carrier (LNGC) cargo hold and block-erection interference areas using 3D scanners have been performed, focusing on large shipyards and the international association of classification societies. In this study, as a part of the research on LNGC cargo hold quality management advancement, a study on deep-learning-based scaffolding system 3D point cloud object detection and post-processing were conducted using a LNGC cargo hold 3D point cloud. The scaffolding system point cloud object detection is based on the PointNet deep learning architecture that detects objects using point clouds, achieving 70% prediction accuracy. In addition, the possibility of improving the accuracy of object detection through parameter adjustment is confirmed, and the standard of Intersection over Union (IoU), an index for determining whether the object is the same, is achieved. To avoid the manual post-processing work, the object detection architecture allows automatic task performance and can achieve stable prediction accuracy through supplementation and improvement of learning data. In the future, an improved study will be conducted on not only the flat surface of the LNGC cargo hold but also complex systems such as curved surfaces, and the results are expected to be applicable in process progress automation rate monitoring and ship quality control.

• BMB Reports
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• 제52권9호
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• pp.566-571
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• 2019

Lymphoma is one of the most curable types of cancer. However, drug resistance is the main challenge faced in lymphoma treatment. Peroxisomal acyl-CoA oxidase 1 (ACOX1) is the rate-limiting enzyme in fatty acid ${\beta}$-oxidation. Deregulation of ACOX1 has been linked to peroxisomal disorders and carcinogenesis in the liver. Currently, there is no information about the function of ACOX1 in lymphoma. In this study, we found that upregulation of ACOX1 promoted proliferation in lymphoma cells, while downregulation of ACOX1 inhibited proliferation and induced apoptosis. Additionally, overexpression of ACOX1 increased resistance to doxorubicin, while suppression of ACOX1 expression markedly potentiated doxorubicin-induced apoptosis. Interestingly, downregulation of ACOX1 promoted mitochondrial location of Bad, reduced mitochondrial membrane potential and provoked apoptosis by activating caspase-9 and caspase-3 related apoptotic pathway. Overexpression of ACOX1 alleviated doxorubicin-induced activation of caspase-9 and caspase-3 and decrease of mitochondrial membrane potential. Importantly, downregulation of ACOX1 increased p73, but not p53, expression. p73 expression was critical for apoptosis induction induced by ACOX1 downregulation. Also, overexpression of ACOX1 significantly reduced stability of p73 protein thereby reducing p73 expression. Thus, our study indicated that suppression of ACOX1 could be a novel and effective approach for treatment of lymphoma.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.115-122
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• 2019

In order to improve the current efficiency and reduce the energy consumption in the electrosynthesis of ammonium persulfate, electrolytic properties of a perfluorosulfonic cation exchange membrane named PGN membrane and the $Al_2O_3$ ceramic membrane in the electrosynthesis of ammonium persulfate were studied and compared in a pilot electrolytic cell using a welded platinum titanium as the anode and a Pb-Sb alloy as the cathode. The effect of cell voltage, electrolyte flow rate and electrolysis time of the electrolytes on the current efficiency and the energy consumption were studied. The results indicated that the PGN membrane could improve current efficiency to 95.12% and reduce energy consumption to $1110kWh\;t^{-1}$ (energy consumption per ton of the ammonium persulfate generated) under the optimal operating conditions and the highest current efficiency of the $Al_2O_3$ ceramic membrane was 72.61% with its lowest energy consumption of $1779kWh\;t^{-1}$. Among 5 times of the electrolysis of the electrolytes, the lowest current efficiency of the PGN membrane was 85.25% with the highest energy consumption of $1244kWh\;t^{-1}$ while the lowest current efficiency of the $Al_2O_3$ ceramic membrane was 67.44% with the highest energy consumption of $1915kWh\;t^{-1}$, which suggested the PGN membrane could be used in the 5-stage electrolytic cell for the industrially continuous electrosynthesis of ammonium persulfate. Therefore the PGN membrane can be efficient to improve the current efficiency and reduce the energy consumption and can be applied in the industrial electrosynthesis of ammonium persulfate.

• Obstetrics & gynecology science
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• 제61권6호
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• pp.649-654
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• 2018

Objective Isotretinoin is a notorious teratogen otherwise used for the treatment of acne vulgaris. Some countries, including those in North America and the European Union, implemented the pregnancy prevention program (PPP); however, no PPP has yet been established in South Korea. So the aim of this study was to evaluate the rate of pregnant women exposed to isotretinoin among the callers of the Korean Mother Safe Counseling Center. Methods This is a prospective cohort study. We evaluated the demographic characteristics, obstetric history, and isotretinoin exposure of pregnant women based on the mother safe registry from April 2010 to July 2016. Results Among 22,374 callers, 650 (2.9%) pregnant women were exposed to isotretinoin. The mean age was $29.0{\pm}4.4$ years in the isotretinoin-exposed group and $32.0{\pm}4.2$ years in the unexposed group (P<0.001). Moreover, the incidence of pregnancies within 30 days after isotretinoin discontinuation or during isotretinoin intake was 78.9% (513/650). The median duration of isotretinoin exposure was 18 (1-4,231) days. Furthermore, from 2011 to 2015, the incidence of isotretinoin exposure was $2.9{\pm}1.2$ pregnancies per 10,000 births in South Korea. Conclusion Approximately 80% of pregnant women are exposed to isotretinoin within the recommended 30 days of contraception or during pregnancy. Therefore, the PPP has to be established in South Korea.